A Millimeter-Wave Mobile Broadband (MMB) system is a millimeter wave based system which operates in a radio frequency range of 30 Gigahertz (GHZ) and 300 GHz. An MMB system uses radio waves with wavelength in range of 1 millimeter (mm) to 10 mm and is a candidate for next generation mobile communication technology due to considerable amount of spectrum available in mmWave band.
Generally, in an MMB system, MMB base stations are deployed with higher density than macro-cellular base stations in order to ensure good network coverage. This is possible as transmission and reception of signals is based on narrow beams which suppress interference from neighboring MMB base stations and extend the range of an MMB link.
Typically, in an MMB network, multiple base stations form a grid with a large number of nodes with which a mobile station can communicate, thereby ensuring high quality Equal Grade Of Service (EGOS) irrespective of the location of the mobile station. The grid having a plurality of base stations serving a mobile station is commonly termed as a virtual cell or a cloud cell. In a could cell, the multiple base stations communicating with a mobile station need to perform downlink transmission beamforming while the mobile station communicating with the base stations need to perform downlink reception beamforming for receiving downlink control information and data packets. Similarly, a mobile station communicating with a base station in a cloud cell may need to perform uplink transmission beamforming while the base station needs to perform uplink reception beamforming for transmitting uplink data.
Further, in a cloud cell, one of base stations acts as a master base station and remaining base stations act as slave base stations with respect to the mobile station. The base stations in the cloud cell serving a mobile station keeps changing dynamically based on movement of the mobile station. The cloud cell thus is a user centric virtual cell. In an overlapping cloud cell scenario, a base station can be a part of more than one cloud cell. In one cloud cell, the base station acts as a master base station for one mobile station and in another cloud cell, the base station act as a slave base station for another mobile station or the base station can act as a master base station for another mobile station.
Generally, in a cellular system of the related art, a mobile station communicates with a single base station and is assigned a unique logical address by the base station. The logical address assigned by the base station distinguishes one mobile station from another mobile station in the domain of the base station that has assigned the logical address. Typically, the logical address assigned to the mobile station is used by the base station for signaling resource allocation information to each mobile station. The logical address in the resource allocation signaling enables the mobile station to determine whether the resource allocation signaling received from the base station is intended for itself or some other mobile station. In addition, the logical address is used by the mobile station in bandwidth request signaling transmitted to the base station. The logical address in the bandwidth request enables the base station to uniquely identify the mobile station from whom the bandwidth request is received. Accordingly, the base station can allocate resources to the mobile station associated with the logical address. Moreover, the logical address assigned to the mobile station is also used to scramble physical layer protocol data units.
In a cloud cell environment, a mobile station communicates with multiple base stations and receives data and control information from multiple base stations. In order to communicate with multiple base stations, each of the base station assigns an individual logical address that is unique across the mobile stations in its domain. The mobile station needs to maintain multiple logical addresses and has to use the logical address specific to the base station with which it communicates. The mobile station can receive/transmit data and control packets from one or more base stations dynamically as directed by the master base station in the cloud cell. This leads to increased complexity at the mobile station as the mobile station has to keep determining the base stations from which it has to communicate and then configure the logical address for transmit/receive processing for determined base stations.
The Medium Access Control (MAC) layer in the mobile station also needs to be aware of the base station with which the mobile station is communicating in order to prepare the control message (e.g., a bandwidth request) and data packets (Security algorithms uses logical address to protect data packets) carrying the appropriate logical address. This would lead to delayed building of data packets and control packets by the MAC layer in the mobile station. In a high speed network, this delayed building of data packets is not desirable for fast processing.
Therefore, a need exists for a method and a system for assigning a logical address to a mobile station in a cloud cell using a disjoint address space.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.